I did this almost a month ago. Basically, got home from a bike ride, put the phone on my bike's saddle (yes, very stupid, I know), opened the garage door, put my stuff away, grabbed the bike and....oh.
The only damage that the drop did was destroying the glass and a minor scuff mark on the black band around the screen. Everything else worked fine, including the touch screen, the LCD itself, the home button, and so on. The only problem was the random tiny shards of glass that kept appearing all the time.
Took it to the Apple store near me and they replaced it, no questions asked, for £119 (out of warranty and with no insurance). Expensive mistake, but thankfully not *too* expensive.